(PhysOrg.com) -- Researchers have demonstrated a new imaging tool for tracking structures called carbon nanotubes in living cells and the bloodstream, which could aid efforts to perfect their use in biomedical research and ...

(PhysOrg.com) -- Football has often been called a game of inches, but biology is a game of nanometers, where spatial differences of only a few nanometers can determine the fate of a cell  whether it lives ...

Berkeley Lab researchers have found a way to make copper-catalyzed click chemistry biocompatible. By adding a ligand that minimizes the toxicity of copper but still allows it to catalyze the click chemistry reaction, the ...

The quest for better ways of encapsulating medicine so that it can reach diseased parts of the body has led scientists to harness -- for the first time -- living human cells to produce natural capsules with channels for releasing ...

Scientists today reported that the tiny light-sensing cells known as rods have been clearly and directly imaged in the living eye for the first time. Using adaptive optics (AO), the same technology astronomers use to study ...

Systems biology is a holistic approach to the study of how a living organism emerges from the interactions of the individual elements that make up its constituent cells. Embracing a broad range of disciplines, this field ...

Biologists at Tufts University School of Arts and Sciences have discovered that a change in membrane voltage in newly identified "instructor cells" can cause stem cells' descendants to trigger melanoma-like growth in pigment ...

By constructing a microscope apparatus that achieves resolution never before possible in living cells, researchers at Albert Einstein College of Medicine of Yeshiva University have illuminated the molecular interactions that ...

Cancer occurs when human cells move and multiply inappropriately. Within cells, a process called phosphorylation serves as an on/off switch for a number of cellular processes that can be involved in cancer, including metabolism, ...

Cell (biology)

The cell is the structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular (consist of a single cell). Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an unfertilized ostrich egg cell.

In 1835 before the final cell theory was developed, a Czech Jan Evangelista Purkyně observed small "granules" while looking at the plant tissue through a microscope. The cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells. All cells come from preexisting cells. Vital functions of an organism occur within cells, and all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.

The word cell comes from the Latin cellula, meaning, a small room. The descriptive name for the smallest living biological structure was chosen by Robert Hooke in a book he published in 1665 when he compared the cork cells he saw through his microscope to the small rooms monks lived in.